Plastic barrel

ABSTRACT

A plastics barrel (10) with a substantially cylindrical barrel wall (12), a disk-shaped barrel floor (14) and a corresponding barrel top (16), in which a closable closure aperture is optionally arranged, and with a circumferential carrying and transporting ring (22), which is arranged on the outer barrel wall (12) in the vicinity of the barrel top (16) and comprises a downward facing horizontal and an inward facing vertical bearing surface (24, 26) for the grab claws of a barrel grab, characterised in that a recessed closure housing (28) with a projecting closure socket (30) is arranged in the centre of the barrel top (16), the internal diameter of the closure socket (30) measuring at least 100 mm or more and this closure socket (30) being closable in a gas-tight and liquid-tight manner by means of a screw lid (32, 34) which can be screwed thereon.

This application is a continuation of Ser. No. 08/341,564 filed Feb. 23,1995 abandoned, which is a 371 of PCT/EP93/0/185 filed May 12, 1993.

FIELD OF THE INVENTION

The invention concerns a plastic barrel having an essentiallycylindrical barrel wall, a flat disk shaped barrel bottom and acorresponding barrel cap in which a bunghole opening that can be sealedmay be incorporated, and having a circumferential carrying and transportring, arranged close to the barrel top on the exterior barrel wall, witha horizontally downward-pointing and vertical inward-pointing supportsurface for the claws of a barrel gripper.

BACKGROUND OF THE INVENTION

Conventional bung barrels with conventional bunghole openings are onlysuitable for the storage and transport of liquids; due to the smallbunghole opening (2 inches), bung barrels are not suitable for viscousor particulate shape goods. Due to the required accessories (large lidand clamping ring), the lid-type drums normally used for the storage andtransport of viscous or solid goods, such as bitumen, paint, fruitconcentrate, granulates, bulk goods and the like, are comparativelyexpensive, in particular for simple applications, such as the transportof granular products like plastic pellets (e.g. EFS=ExpandablePolystyrene), and they have worse dropping characteristics than closedbung barrels.

SUMMARY OF THE INVENTION

It is the task of the present invention to indicate a plastic barrelwhich is particularly suitable for the transport of viscous or granularproducts.

It must be possible to produce the barrel at low cost, and it must bepossible to handle it by means of the usual barrel gripping tools.

According to the invention, this task is solved by arranging a recessedbung housing with a bunghole neck centered in the barrel cover of ageneric plastic barrel, the bunghole neck diameter being at least 100 mmor more. A preferred design provides for a bunghole neck diameter ofapprox. 150 mm. In another special design, the diameter of the bungholeneck is approx. 225 mm. It is of advantage that only these diameters areused for the various barrel sizes (e.g. 120 1, 220 1) uniformly. TheL-ring barrel according to the invention, which has a centeredscrew-cap, can be produced at lower cost compared to a normal standardcover barrel, and it has better dropping characteristics than thelatter. Compared to the large barrel cover, the screw-type barrel capscan also be made at lower cost (since they are only offered in twosizes), and the cost for an additional clamping ring is also eliminated.Therefore, it is possible to offer low-cost screw-cap barrels both forthe above-mentioned application with particulate products andgranulates, respectively, and for filling in lumpy foodstuff or viscousfruit concentrates with lumps of fruit. Compared to lid-type drums,there are additional advantages since the screw-cap barrels according tothe invention, having the top carrying and transport ring (MauserL-ring), can be handled and manipulated by means of the same barrelgripping tools as those for normal bung barrels of steel or plastic.

In the preferred design, the complete barrel is blow-molded in onepiece. Naturally, the barrel can be welded together from two (or three)parts, such as a separately injection-moldedtop (and possibly a moldedbottom) and an extruded cylindrical basic barrel body.

In addition, the barrel according to the invention may also be fittedwith a circumferential, stable floor rolling ring at the bottom barreledge, at the transition between the exterior barrel wall and the flatbarrel bottom.

It is an important feature of the invention that, regardless of thecapacity of the L-ring barrels (e.g. 60 1, 120 1, 150 1, 160 1 or even220 1), the dimensions of the two preferred sizes of th e screw-capcover are retained. The smaller version of the screw-cap has an outsidediameter of approx. 180 mm while the outside diameter of the largerscrew-cap is approx., 270 mm.

In the present case, the bunghole neck has an outside thread for thescrew-cap which according to the invention has an inside thread; whereasthe usual, small 2-inch bunghole necks of normal bung barrels alwayshave inside threading and the appertaining bung plug has a correspondingoutside thread.

An expanded concept of the invention provides for the upper plane of thescrew-cap, which is screwed onto the bunghole neck, to be arranged atthe same height or almost flush with the barrel top or below the barreltop.

Hence, the screw-cap recessed in the center of the barrel top in a bungdepression has optimum protection in the event that the barrel isdropped and will never have direct floor contact.

BRIEF DESCRIPTION OF THE DRAWINGS

Below, the invention is explained and described by means of the designexamples presented schematically in the drawings.

FIG. 1 shows a screw-cap barrel according to the invention in a sideview, partly as sectional view;

FIG. 2 shows the top edge area of a barrel with the large screw-cap;

FIG. 3 shows the top edge area of a barrel with the small screw-cap;

FIG. 4 shows the top edge area of a barrel with the small screw-cap andadditional bunghole for complete draining;

FIG. 5 shows a top view of a screw-cap barrel according to theinvention;

FIG. 6 shows a perspective view of another screw-cap barrel according tothe invention;

FIG. 7 shows a cross-sectional view of the barrel head of FIG. 6, and

FIG. 8 shows a top view of another design of a screw-cap barrel.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1, reference number 10 designates a plastic barrel according tothe invention (HOT barrel), having a cylindrical barrel wall 12, a diskshape barrel bottom 14 and a corresponding barrel top 16. In thetransition area between the barrel top 16 and the outer barrel wall 12,a circumferential carrying and transport ring 22 with a horizontaldownward-pointing support surface 24 and a vertical inward-pointingcounter-support surface 26 for the gripping claws of a commercial barrelgripper for steel drums is provided.

Centered in the barrel top 16, a recessed bung housing 28 with abunghole neck 30, which protrudes from the level bung housing floor 40,and is provided with an outside thread. The inside diameter of thebunghole neck 30 and of the bunghole opening 20 (18), respectively, isat least 100 mm or more (larger) and is closed gas-and liquid-tight bymeans of a screwed-on screw-type cap 34 (32) having the correspondinginside thread at the edge of the flange.

The smallest inside diameter of the bunghole neck should not be below100 mm, because the opening should at least be large enough that one isable to pass one's hand through it. Of course, this minimum opening isvery advantageous for complete inside cleaning of the barrel if it isused several times. On the other hand, the bunghole opening should notbe significantly larger than half the barrel diameter; in that case, thecost advantage would be lost and the drop resistance may be decreased,for example because strong elastic deformation of the top may causeleakage of the screw-cap.

In FIG. 2, the top part of the barrel with the larger bunghole opening18 is shown, where the bung neck 30 has an inside diameter of approx.225 mm. Measured in the upper plane of the barrel top, the diameter ofthe bung housing is between 300 mm and 400 mm, preferably approx. 330mm, and the diameter of the level bung housing floor is between 250 mmand 330 mm, preferably approx. 270 mm. The larger screw-cap 32, havingan outside diameter of approx. 270 mm, may be provided on its surfacewith projecting circumferential ribs permitting the use of a wrench.

The other, preferred design with the smaller bunghole opening 20, havingan inside diameter of the bung neck 30 of approx. 150 mm, is shown inFIG. 3. In this case, the diameter of the bung housing, measured at theupper plane of the barrel top, is between 200 and 300 mm, preferablyapprox. 230 mm, and the diameter of the level bung housing floor isbetween 180 mm and 250 mm, preferably approx. 190 mm. The smallerscrew-cap 34, having an outside diameter of approx. 180 mm, preferablyhas a level surface. The flat, disk-shaped surface of the screw-cap isconnected to a flange edge having a height of approx. 40 mm. andextending at a right angle. The outside of the flange edge is filletedor knurled for improved manual grip when the cover is screwed on. Theflange edge has an inside thread, and the bunghole neck 30 has acorresponding outside thread. At a small distance from the flange edge,a second flange ring, which is a little shorter, is provided which alsoextends at a right angle. There is a circumferential U-shape groovebetween the outer and the inner flange edge. Into this groove a gasketis inserted to seal the screw cover against the upper face edge of thebunghole neck 30.

In this design, the upper plane of the screw-cap, which is screwed ontothe bunghole neck, extends between the upper plane of the barrel top andthe upper plane of the upper face edge of the carrying and transportring 22.

In a design, which is not drawn in detail, the upper plane of the barreltop lies above the upper plane of the face edge of the carrying andtransport ring.

In this case, a supporting internal pressure is built up in the lowerbarrel which is advantageous when barrels of the same type are stacked,before the stack load is transferred to the carrying and transport ring.

In FIG. 4, another design according to the invention is shown in apartial section, where the barrel top 16, in addition to thelarge-drawer screw-cap opening (18, 20), is provided with a second,small bunghole opening 38, which can be closed, to the side of theformer for completely emptying the barrel contents. It is useful thatthis bunghole opening 38 remains initially closed at the bottom (inside)in the blow molding process. Only when required, lateral bores can bedrilled in the threaded neck, or the disk-shaped bottom of the threadedneck is cut out. The bunghole opening 38 can be closed by a suitableconventional bung plug. In the design shown, the upper plane of thebarrel top 16 is arranged below the top edge 36 of the carrying andtransport ring 22, while the screw-cap 34 projects a little beyond thebarrel top 16.

This design effects a central support and a circumferential support ofstacked barrels of the same type.

However, in a variation of the design, the face edge 36 of the carryingand support ring 22, the barrel top 16 and the screw-cap 32, 34 on thebunghole neck 30 may also be arranged in essentially the same plane.

FIG. 5 shows a top view of the barrel design according to FIG. 4. Theadditional bunghole opening 38 may be provided, which need not be thecase, however, when used for granular goods, for example.

In a further-developed design--shown in FIG. 6--the barrel top 16 isprovided with at least one radial water drain groove 42, which opensinto the bung housing 28 on the inside and into the gripping groove 44,which runs behind the carrying and transport ring 22 in the direction ofits circumference on the outside.

This prevents, for example, that larger amounts of rain water collect inthe bung housing 28 if this type of barrel is stored outside. In thismanner, collecting rain water can run off through the groove 42 from thebung housing 28 into the lower gripping groove 44 behind the carryingand transport ring 22. In at least one place, preferably in severalplaces, water drain holes, which open into the bottom of the grippinggroove 44, are arranged through the connecting rib of the carrying andtransport ring, so that rain water can never collect in the grippinggroove 44 itself.

In FIG. 7, another feature according to the invention is realized. Inorder to improve the complete drainage of the barrel in a positioninverted by 180', the barrel top has a slight overall slope. Seen in thenormal position of the barrel, the side having the additional residualdrainage bunghole opening 38 is between 2 mm and 12 mm, preferably about8 mm, higher than the side opposite the smaller bunghole opening 38.

The height difference of about 8 mm is also indicated in FIG. 4 by meansof the dashed height line of the lower barrel top region and thedistance arrows pointing at it at right angles. When barrels of thistype are stacked, there is central support through the screw-cap 32 andcircumferential support through the carrying and transport ring 22 ofthe bottom barrel.

In order to also achieve stack support in the region of the intermediatebarrel top, crown elements 46 may be arranged on the surface of thebarrel top as shown in FIG. 8, where the top of the crown elements 46are flush with the carrying and transport ring 22. In the design shownin FIG. 8, eight ribbed crown elements 46 at uniform distances areprovided. Naturally, the crown elements may have a different shape, e.g.rectangular or square, and they may be incorporated at the time thebarrel is blow-molded, or they may be glued or welded on later asseparately made injection-molded parts. It is even simpler to form theentire barrel top with carrying and transport ring, bung neck and crownelements by the injection molding process, whereupon the barrel top iswelded onto the basic barrel body.

Hence, the screw cap barrel according to the invention is excellentlysuited for particle and liquid goods. The large container opening isalso advantageous for using an agitator (twirling stick), e.g. withproducts tending to separate (e.g. zinc oxide paint), which need to bemixed and homogenized before being removed. The barrel is also suitablefor multiple use because, in contrast to conventional bung barrels, itmay be cleaned inside.

In addition, the large container opening for the first time makes itpossible to use without problems a thin-wall plastic inliner for aclosed L-ring barrel.

Finally, in order to extend the application of the screw-cap L-ringbarrel to the use with goods tending to outgas, the screw cap 32 itselfis provided--as indicated in FIG. 8--with a bung plug 50 fitted with aventing device 48, which prevents an overpressure from building upwithin the barrel.

Generally, the screw-cap L-ring barrel according to the invention maynaturally also be equipped with a circumferential floor rolling ring.

We claim:
 1. In a plastic barrel (10) of thermoplastic material, havingan essentially cylindrical barrel wall (12), with a disk-shaped barrelbottom (14) and a corresponding barrel top (16) having a center and apredetermined diameter, a closable bunghole opening in said barrel top,and a carrying and transport ring (22) with a top edge and horizontaland vertical support surfaces (24, 26), respectively, facing radiallyinwardly and downwardly, provided near the barrel top (16) on theoutside barrel wall for the gripping claws of a barrel gripper, saidcarrying and transport ring (22) circumferentially surrounding saidbarrel top (16) and radially spaced therefrom, the improvementcomprising:a) a projecting bunghole opening neck (30), defining thebunghole opening located in the barrel top in alignment with the centerof said top and projecting upwardly from said barrel top, said bungholeneck (30) having an external surface with an external thread and aninside diameter of at least 100 mm and no larger than about one-half thediameter of said barrel top; and b) a screw cap (32, 34) with aninternal thread removably screwed onto said bunghole neck (30), with thecap having an internal surface in sealing engagement with the externalsurface of said bunghole neck for closing said bunghole opening in a gasand liquid-tight manner.
 2. Plastic barrel according to claim 1,characterized by the fact that the inside diameter of the bunghole neck(30) is approximately 150 mm, and the screw cap has an outside diameterof approximately 180 mm.
 3. Plastic barrel according to claim 1,characterized by the fact that the inside diameter of the bunghole neck(30) is approx. 225 mm, and the screw-cap has an outside diameter ofapproximately 270 mm.
 4. Plastic barrel according to claim 2,characterized by the fact that the bunghole housing 28 includes a bunghousing floor (40), the diameter of the bung housing (28), measured atthe barrel top (16), is between 200 and 300 mm, preferably approximately230 mm, and the diameter of the bung housing floor (40) is between 180mm and 250 mm, preferably between 190 mm.
 5. Plastic barrel according toclaim 3, characterized by the fact that the bunghole housing 28 includesa ban housing floor (40), the diameter of the bung housing (28),measured at the barrel top (16), is between 300 and 400 mm, preferablyapproximately 330 mm, and the diameter of the bung housing floor (40) isbetween 250 mm and 330 mm, preferably between 270 mm.
 6. Plastic barrelaccording to claim 1, characterized by the fact that the screw-cap (32),when screwed on to the bunghole neck (30), has an upper surface which isat a level no higher than the barrel top (16).
 7. Plastic barrelaccording to claim 1, characterized by the fact that the screw cover(32), when screwed on to the bunghole neck (30), has an upper surfacewhich is at a level which extends between the barrel top (16) and thetop edge (36) of the carrying and transport ring (22).
 8. Plastic barrelaccording to claim 1, characterized by the fact that the barrel top (16)lies above the top edge (36) of the carrying and transport ring (22). 9.Plastic barrel according to claim 1, characterized by the fact that thebarrel top (16) lies below the top edge (36) of the carrying andtransport ring (22).
 10. Plastic barrel according to claim 1,characterized by the fact that the top edge (36) of the carrying andtransport ring (22), the barrel top (16) and the screw cap (32, 34)screwed onto the bunghole neck (30) lie in essentially the same plane.11. Plastic barrel according to claim 1, characterized by the fact thatan additional, second small bunghole opening (38) for removing the restof the barrel content is provided in the barrel top (16).
 12. Plasticbarrel according to claim 11, characterized by the fact that the barreltop (16) has a slight overall slope when viewed in the normal uprightposition of the barrel, the side having the additional residual drainagebunghole opening (38) is between 2 mm and 12 mm, preferably about 8 mm,higher than the side opposite the smaller bunghole opening (38). 13.Plastic barrel according to claim 1, characterized by the fact that thebarrel top (16) is provided with at least one radial water drain groove(42), which opens into the bung housing (28) on the inside and into agripping groove (44), which runs behind the carrying and transport ring(22)in the direction of its circumference on the outside.
 14. Plasticbarrel according to claim 1, characterized by the fact that the barreltop (16) is provided with at least two or more preferably ribbed crownelements (46) at uniform distances.
 15. Plastic barrel according toclaim 1, characterized by the fact that the lower barrel edge hasprovisions for a stable circumferential floor rolling ring in thetransition area from the outside cylindrical barrel wall (12) and theflat barrel bottom (14).
 16. Plastic barrel according to claim 1,wherein the bunghole neck (30) has an upwardly facing edge defining atleast part of the external surface which is in engagement with saidinternal surface of said cap (32,34) to close said bunghole opening insaid gas and liquid-tight manner.